In arid continental regions of the world proximate to water sources such as salt water or on an island having deficient water supplies, e.g., Bermuda, a ready source of water would be sea water or brackish well water were it not for the high cost of obtaining salt-free water from these sources.
A great effort has been expended to develop various processes for this purpose, e.g., evaporation, amine solvent extraction, reverse osmosis, etc. In fact, in the United States the Office of Saline Water was established within the Department of Interior to investigate and find new methods for water recovery. In other countries where obtaining water is of national concern, similar governmental institutions exist.
Consequently, as a result of these efforts and activity, a number of publications and patents have come into existence. The literature collection concerning water recovery is fairly large. This literature relates to various desalination methods and practices and illustrates schematically a number of processes.
However, for purposes of background understanding, the present invention relates to a method pertaining to the use of heretofore unknown family of hydrogels for absorbing water from sea water, brackish water or brackish well water and the like (collectively "saline water"), the removal of the hydrogels from the saline water and the expelling from the hydrogels of water of substantially reduced salinity and recovery methods associated therewith.